So I have this back seat which is one big cushion. When you step on it or sit on it, it basically has no structure. I am having some vinyl work done this winter, and would like to rebuild the rear seat to sit up on the ledges on each side of the boat and use a support under the center in the middle. The other seats utilize a thick plastic material. Would be nice to find a sheet of that material and build from that.

Here are a few photos of what I have. The current seat sits so low and I can't leave it there while towing or it would possibly fly out!

Any suggestions or pictures of your Sportstar/Prostar back seat would be great!!
Thanks

The material used in my 94 PS 205 seems a little more dense than the Starboard and may hold a screw a little better plus you could probably get by with a little thinner sheet, but either way it is still an extruded plastic of some type. You may need to have some kind of support leg in the middle, as that is a pretty long span.

Yea, I would probably make some type of support in the center just trying to avoid using any wood even marine stuff. Thanks for the suggestion I will have to look into some plastics for the seat bottem.